Dawn phenomenon | ScienceGate

Abstract Purpose To investigate how the pattern of sedentary behaviour affects intra-day glucose regulation in type 2 diabetes. Methods This intensive longitudinal study was conducted in 37 participants with type 2 diabetes (age, 62.8 ± 10.5 years). Glucose and sedentary behaviour/physical activity were assessed with a continuous glucose monitoring (Abbott FreeStyle Libre) and an activity monitor (activPAL3) for 14 days. Multiple regression models with generalised estimating equations (GEEs) approach were used to assess the associations of sedentary time and breaks in sedentary time with pre-breakfast glucose, pre-lunch glucose, pre-dinner glucose, post-breakfast glucose, post-lunch glucose, post-dinner glucose, bedtime glucose, the dawn phenomenon, time in target glucose range (TIR, glucose 3.9–10 mmol/L) and time above target glucose range (TAR, glucose > 10 mmol/L). Results Sedentary time was associated with higher pre-breakfast glucose (p = 0.001), pre-dinner glucose (p < 0.001), post-lunch glucose (p = 0.005), post-dinner glucose (p = 0.013) and the dawn phenomenon (p < 0.001). Breaks in sedentary time were associated with lower pre-breakfast glucose (p = 0.023), pre-dinner glucose (p = 0.023), post-breakfast glucose (p < 0.001) and the dawn phenomenon (p = 0.004). The association between sedentary time and less TIR (p = 0.022) and the association between breaks in sedentary time and more TIR (p = 0.001) were also observed. Conclusions Reducing sedentary time and promoting breaks in sedentary time could be clinically relevant to improve intra-day glucose regulation in type 2 diabetes.

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Analysis of Prevalence, Magnitude and Timing of the Dawn Phenomenon in Type 1 Diabetes: Descriptive Analysis of 2 Insulin Pump Trials

Canadian Journal of Diabetes ◽

10.1016/j.jcjd.2018.08.024 ◽

2018 ◽

Vol 42 (5) ◽

pp. S8

Author(s):

Ilia Ostrovski ◽

Leif Erik Lovblom ◽

Daniel Scarr ◽

Alanna Weisman ◽

Nancy Cardinez ◽

...

Keyword(s):

Type 1 Diabetes ◽

Insulin Pump ◽

Descriptive Analysis ◽

Dawn Phenomenon

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Suppression of Sleep-Induced Growth Hormone Secretion by Anticholinergic Agent Abolishes Dawn Phenomenon

Diabetes ◽

10.2337/diab.37.2.166 ◽

1988 ◽

Vol 37 (2) ◽

pp. 166-171 ◽

Cited By ~ 17

Author(s):

M. B. Davidson ◽

M. D. Harris ◽

F. H. Ziel ◽

C. S. Rosenberg

Keyword(s):

Growth Hormone ◽

Hormone Secretion ◽

Growth Hormone Secretion ◽

Anticholinergic Agent ◽

Dawn Phenomenon

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Absence of the Dawn Phenomenon in Normal Subjects

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem-67-1-203 ◽

1988 ◽

Vol 67 (1) ◽

pp. 203-205 ◽

Cited By ~ 12

Author(s):

C. SIMON ◽

G. BRANDENBERGER ◽

M. FOLLENIUS

Keyword(s):

Normal Subjects ◽

Dawn Phenomenon

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Daily Fasting Blood Glucose Rhythm in Male Mice: A Role of the Circadian Clock in the Liver

Endocrinology ◽

10.1210/en.2015-1376 ◽

2015 ◽

Vol 157 (2) ◽

pp. 463-469 ◽

Cited By ~ 15

Author(s):

Hitoshi Ando ◽

Kentaro Ushijima ◽

Shigeki Shimba ◽

Akio Fujimura

Keyword(s):

Blood Glucose ◽

Circadian Clock ◽

Mrna Expression ◽

Hepatic Glucose Production ◽

Critical Role ◽

Fasting Blood Glucose ◽

Glucose Production ◽

Diabetic Patients ◽

Dark Phase ◽

Dawn Phenomenon

Abstract Fasting blood glucose (FBG) and hepatic glucose production are regulated according to a circadian rhythm. An early morning increase in FBG levels, which is pronounced among diabetic patients, is known as the dawn phenomenon. Although the intracellular circadian clock generates various molecular rhythms, whether the hepatic clock is involved in FBG rhythm remains unclear. To address this issue, we investigated the effects of phase shift and disruption of the hepatic clock on the FBG rhythm. In both C57BL/6J and diabetic ob/ob mice, FBG exhibited significant daily rhythms with a peak at the beginning of the dark phase. Light-phase restricted feeding altered the phase of FBG rhythm mildly in C57BL/6J mice and greatly in ob/ob mice, in concert with the phase shifts of mRNA expression rhythms of the clock and glucose production–related genes in the liver. Moreover, the rhythmicity of FBG and Glut2 expression was not detected in liver-specific Bmal1-deficient mice. Furthermore, treatment with octreotide suppressed the plasma growth hormone concentration but did not affect the hepatic mRNA expression of the clock genes or the rise in FBG during the latter half of the resting phase in C57BL/6J mice. These results suggest that the hepatic circadian clock plays a critical role in regulating the daily FBG rhythm, including the dawn phenomenon.

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Rarity of a Marked "Dawn Phenomenon" in Diabetic Subjects Treated by Continuous Subcutaneous Insulin Infusion

Diabetes Care ◽

10.2337/diacare.8.1.28 ◽

1985 ◽

Vol 8 (1) ◽

pp. 28-33 ◽

Cited By ~ 30

Author(s):

J. J. Bending ◽

J. C. Pickup ◽

A. C. G. Collins ◽

H. Keen

Keyword(s):

Continuous Subcutaneous Insulin Infusion ◽

Insulin Infusion ◽

Subcutaneous Insulin ◽

Dawn Phenomenon

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Pathogenesis and Prevention of the Dawn Phenomenon in Diabetic Patients Treated with CSII

Diabetes ◽

10.2337/diab.35.1.78 ◽

1986 ◽

Vol 35 (1) ◽

pp. 78-82 ◽

Cited By ~ 42

Author(s):

V. A. Koivisto ◽

H. Yki-Jarvinen ◽

E. Helve ◽

S.-L. Karonen ◽

R. Pelkonen

Keyword(s):

Diabetic Patients ◽

Dawn Phenomenon

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Poor Sleep Quality Is Associated with Dawn Phenomenon and Impaired Circadian Clock Gene Expression in Subjects with Type 2 Diabetes Mellitus

International Journal of Endocrinology ◽

10.1155/2017/4578973 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Yuxin Huang ◽

Haidong Wang ◽

Yuan Li ◽

Xiaoming Tao ◽

Jiao Sun

Keyword(s):

Sleep Quality ◽

Circadian Clock ◽

Clock Gene ◽

Clock Genes ◽

Poor Sleep ◽

Poor Sleep Quality ◽

Clock Gene Expression ◽

Dawn Phenomenon ◽

Circadian Clock Genes ◽

Good Sleep

Aims. We investigated whether poor sleep quality is associated with both dawn phenomenon and impaired circadian clock gene expression in subjects with diabetes. Methods. 81 subjects with diabetes on continuous glucose monitoring were divided into two groups according to the Pittsburgh Sleep Quality Index. The magnitude of dawn phenomenon was quantified by its increment from nocturnal nadir to prebreakfast. Peripheral leucocytes were sampled from 81 subjects with diabetes and 28 normal controls at 09:00. Transcript levels of circadian clock genes (BMAL1, PER1, PER2, and PER3) were determined by real-time quantitative polymerase chain reaction. Results. The levels of HbA1c and fasting glucose and the magnitude of dawn phenomenon were significantly higher in the diabetes group with poor sleep quality than that with good sleep quality. Peripheral leucocytes from subjects with poor sleep quality expressed significantly lower transcript levels of BMAL1 and PER1 compared with those with good sleep quality. Poor sleep quality was significantly correlated with magnitude of dawn phenomenon. Multiple linear regression showed that sleep quality and PER1 were significantly independently correlated with dawn phenomenon. Conclusions. Dawn phenomenon is associated with sleep quality. Furthermore, mRNA expression of circadian clock genes is dampened in peripheral leucocytes of subjects with poor sleep quality.

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